Sanitary pump



April 7, 1953 F. coLLURA 2,633,807

Y SANITARY PUMP Filed June 20. 1947 Y 2 SHEETS-SHEET 1 April. 7, 1953 F. COLLURA 2,633,807

` SANITARY PUMP Filed June 20. 194'? 2 SHEETS- SHEET 2- lizing purposes.

Patented Apr. 7, 1953 SANITARY PUMP Francesco Collura, New York, N. Y., assignor to Waterous Company, St. Paul, Minn., a corporation of Minnesota Application June 20, 1947, Serial No. 755,851

(Cl. 10S-126) 8 Claims.

The present Vinvention' relates to an improve- Yment in sanitary pump wherein itis desired to ,provide a pump capable for use in pumping milk,

foodstuffs or the like.

Pumps designed for usefor pumping foodstuffs or similar materials must be so constructed that they can be easily cleaned and sterilized. It is also desirable that such pumps be so manufactured that the parts of the pump in contact with material pumped `may be quickly removed for cleaning and sterilizing purposes'. It is also desirable that such pumps be made with a minimum number of parts to be removed so that the task of cleaning and sterilizing the pump may provide a pump which may beused for pumping foodstuffs or the like and which may be quickly and easily taken apart for cleaning and steri- By removing an end closure plate of the pump all of the parts which come in contact with the material being pumped are rendered readily accessible for easy removal and for cleaning purposes.

A feature of the present invention resides in the provision of a bearing structure which firmly holds the impeller shafts during rotation thereof. The pump is provided with two parallel shafts which rsupport rotating interacting impellers to produce the pumping action. These shafts are rotated in unison in opposite rotative directions by meshing gears mounted on the two shafts. Bearings are provided on each side of the gears so as to firmly support the shafts during rotation thereof.

A feature of the present invention lies in the provision of an outboard bearing which is supported by the removable pump end and which assists in supporting the free ends of the shafts during rotation thereof. The rotatable pistons Y are supported between an intermediate bearing tween the gear casing enclosing the meshing gears and the projecting ends of the shafts which support the impellers. As a result none 0f the oil' or grease within the gear boX is allowed to 'enter the pumping area and none of the material being pumped is allowed to enter the gear box. 1

A further feature of the invention lies in the provision of outboard bearings which are sepa- ...rated from the pump chambers by. means Vof a liquid tight seal. `puvmpeddis. held within the pump chambers andV As a result the uid being is not allowed to enterl the shaft supporting bearings.

A further feature of the present invention resides in the provision of a replaceable sealing ring Ywhich may be replaced when worn without the necessity of machining the portions of the casing against which the sealing rings engage.

The seals are so devised that considerable wear may take place before it will become necessary to machine the wearing surfaces on the pump housing.

A further lfeature ,of the present invention resides in the elimination of any threads Within the liquid chamber of the pump. This is an important feature as it eliminates the tendency for food particles to become lodged in inaccessible and hard to clean threads.

These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims. i

In the drawings forming a part of my specification: l

Figure l is an end elevational view of the pump showing the construction thereof. l

Figure 2 is a vertical sectional view through Vthe pump, the position of the section being indihousing showing theV construction.

The pump A includes a drive shaft I0 and a parallel shaft II supported in spaced parallel relation by a gear casing or housing indicated in general by the numeral I2. A pinion I3 on the drive shaft It engages a similar pinion I4 on the shaft Il so as to drive the shafts I0 and I I in opposite rotative directions in unison. The pump action is provided by interacting impellers mounted on the shafts I0 and II as will be later described in detail.

The gear casing I2 includes a peripheral wall I5 having an end wall It at one end thereof and a second end wall Il at the other end thereof. A pair of sleeves I9 and 20 are supported by the end wall I'I in coaxial relation with the shafts I0 and II respectively. s A ball bearing 2l is interposed between the sleeve I9 and the shaft I0. A similar ball bearing 22 is interposed between the sleeve 20 and the shaft I I. Theinner The end wan ls is provided with a pair er apertures 30 and 3| therein. The aperture r3@ is coaxial with the shaft lill,y while' the aperture 3| is coaxial with the shaft vrI I. A bushing 32 is provided in the aperture '30; 32 is provided with a peripheral flange 33 which overlies a portion of the outer surface of the end wall I6 throughout most of the circumfer- Thi's 'bushing thereof. The vent 64 is designed as illustrated to permit pressure to equalize on opposite sides of the cover plate Ell without permitting water or the like to flow into the pump casing.

An oil seal t5 encircles the enlarged diameter portion 23 of the shaft I0 and is interposed between the shaft I and the sleeve I9 externally of the bearing 52|. The o'il seal B5 is'to prevent oil from y'leaking through the' end walll I1 from the gear chamber I2. A sealing disc 66 encircles the shaft I externally of the oil seal 65 to further enclose the seal and to prevent the escape of oil ence of the bushing 32. An inwardly 'extending liange 34 is provided at the other end of the bushing`32 for a Y'purpose which Vwill be later described. n

'A bushing 35 is provdedin:the'laperture 3|. This bushing 35 is provided with va marginal flange 33 extending about 'most ofthepe'riphery of the bushing. An inwardly extending'ilangel `is provided at the Yopposite end of "the bushing.

A pair of opposed thrust `bearings te an'dilare provided between the bushing 32 and the reduced diameter portion AII ofthe shaftV i.' The inner races of the bearings 39 and 4I) are clamped betwee-'n a shoulder z|12 at thevend-of Ithe reduced diameter portion :III 'and a clamping nutflit en- `gaged upon the threaded portion it of 'the shaft ii). The vouter races'of 'the bearings 39 and 140 are engaged between the flange-34 `and 'a clamping ring &5 secured tothe` bushing 32 by bolts i6 or similar means. Thus the-bearings Se 'and 40 are held fixedfrorn longitudinal movement relative :to the vgear-casing and are also fixed from longitudinal movement on the shaft IU," thus holding the sha'ftfrom appreciabler endf'movement.

A similar means isvprovided to hold the'shaft Y II "from longitudinal' movement 'relative tev the gear casing. pair of opposed thrustbearings fland 5S arernountedupon a reduced'diameter portion 5t of the shaft II.`, Theinnerrace's of these bearingsflll Yand 49 areclampedfbetween the shoulderil 'at ther end ofthe reduce Adiameter shaft portion-'A50 and Vva clamping nut-52 supported 'on the-thr'ear'led:portionV 5310i the shaft.

The outer races of these bearings lif'lland '49 are clamped between the flangeSljand aclamping ring V5|| 4secured'to the bushing 35 byciamping nuts' or other suitable'm'eansf A inger rin'g'S'Iis mounteduponthe. shaft I0 between the'lpinion I3 and vtlie inn'eifr'ace-of the pearingt. vThus theiinger rings fandf51,"the pinion I3 and the innerrace of the -bearing 2| are held `from ylongitudinal movementzon Athe the casing' cover 60 `andanoil'seal B2 is provided between a'hub A63 encircling'the's'haft I0 andthe surface of the shaft. Avent opening -comprisirig"two"fangularlyextending passages extends through the cover BOnear theupperfextreniity vare preventedA fromalongitudinal?movemen l sealing g .means is inter-posed lcetzveenleachy i-I'nfrcmrthe gear casing.

Anoils'eal -t'l is interposed between the shaft II and the sleeve. The disc 69 is mounted on the 'shaft'II adjacent this seal G'I. rThe seal 61 and disc '63 prevent oil from leaking from the gear chamber and into the pump chamber. The discs 68 and 69 also prevent liquid from the pump chamber from leakingv into the gear chamber. As vwill be Vnoted the-inner surface iof .the discs 66 and S9 areienclosedin; recessesintthelendiwall ILwhile theoppcsite surfacesofthese discsare externally of the recesses.

A pair of dowel pins'IO an'dIIiare mounted in aperturesZand I3'at'the topandtbott'cm ends of the endwall Il voffthegear casing. These dowel pins act to guide the pumpichamber'oasting and the cover. member'therefor intoproper 4position relative v.toithe gear housing. Studs Mfiextend 'frornthe gear casing end wall IIatperipherally spacedv points. kThe fouteraends'offthese studs i4 are threaded to'accomrnodatelwingfnuts I5 to hold Vthe pump .partsassembled .asfvivillllbe later described in detail. r 1

The Jpump casing .13 vis v.formed asbest illustrated in Figures 2, '3, and '4 of thevldrawings. The pump casing I6 is'wideriat itsperipherylzthan throughout ythe :remainder 'of its 'body1 Iso asirto peripherally engage against the endf wall 5| l' fof the gear housing. A pair of'substantiallyfcylindrical impeller apertures 'ilnandfl .'-areforrned within rthe pump `casing 1.6 Vconcentric-.'vvitl1.fthe shafts I0 and II respectively. .Tubulaz2bosses180 and SI whichfare concentric with the .shafts I0 and I I project forwardlyfromthe bodywall i12-.lof the pump housing.. AsV arresult the-pump'ffhou'sing includesia `pair Tof intersecting ri'n'gishaped chambers inwhichthe crescent shaped' impelle'rs 83 yand "86 may rotate. .The inner surfaceofthe impellers 83 and :34 .L rotate Yabout fthe bosses'l and 8| respectively. 'Therouterisurfacesoflthese ycrescent lshaped impel'lers 83 and 84`-^contactlthe inner 1 surfaces of; they impeller chambers. 'ILT' and l. A portion of each boss and SI is cutaway to .permit 'thexshafts 1.I0 rand 5| I Vto bellcloserV together ythan would.otherwise"be'.po'ssible.r

The impellers'izandi are mounted upon supporting discs 85 .andf 86,fresp'ectively,.lwhich,initurn vare provided Vwith elongatedhubsllt'Iy and 89". .The

hubs 581 and 89^are :spline"connected to the 1reduced diameter portions .90 and' SI r-of the shafts I and II .respectivelyj "The-hub -BILi's'l-hfeld clamped betweenfthefshoulder 92 atithe "end of thefre'duced diameter :portion 902 o'fthe shaft 4"I Il, and aclampinglnutii 'mounte'dron thethreaded portion 94 ofthezslrraft'.Ii. TheihubS .off-:the impell'er k84 is :clamped betweenltheshoulderl 95 at the endy .of thezireduc'ed diameterportionr I 1 of Vthefshaftl I and aclampingnut-Son thefthread- -ed portion ofthe'shaft 'II. Thusth'enipellers are r held supported bythe zslia'fts im 1 and 1 |g, and

peller support andl'the sleeve about which theimpeller rotates. This! sealing ring construction is best illustrated in Figure 5 of the drawings. The internal diameter of the boss 80 is of proper size to fit yfreely about the portion of the shaft I which it embraces. Thus the aperturev 99 within the boss 80 is somewhat spaced from Vthe outer surface of the shaft |0. An aperture |00 of somewhat larger diameter than thev aperture 99 extends a portion of the way through the boss 80 from the free end thereof. The boss 80 is undercut at l0| to provide a shoulder |02 against which an effective seal may be produced.

The seal includes a flexible washer |03 Yofneoprene which is corrugated between itsl ends so as having a peripheral flange |05 of a diameter to nt within the aperture |00. The washer |04 is likewise provided with a projecting shoulder |06 designed to bear against the projecting portion |02 of the boss 80. The washer |04 rotates with the flexible washer |03, which of course rotates in unison with the shaft I0 and the impeller support 85. The bearing ring |04 rotates relative to the fixed shoulder |02 and assists in the formation of an effective fluid seal.

The boss 8| is likewise provided with a two diameter aperture |01 therethrough in which is positioned a seal |09 similar to the seal previously disclosed and illustrated in Figure 5 of the drawings.

A closure plate ||0 is provided adjacent the pump housing to close the forward ends of the impeller chambers and to provide an additional bearing for Vthe shafts i0 and This closure plate ||0 abuts against the forward edge of the pump housing 16 4and acts as a closure for the chambers 11 and 19. A pair of cylindrical recesses and ||2 are provided in the cover plate conf centric with the shafts I0 and to accommodate the disc shaped impeller supports 85 and-86. The plate ||0'is also provided with outwardly projecting tapered tubular projections |3 and ||4 which are concentric with the shafts I0 and Bearing sleeves |I5 and ||6 are mounted within the ends of the tubular projections ||3 and ||4 to form a support for the forward extremities of the shafts I0 and The tubular projection ||3 is provided with an aperture ||1 concentric with the shaft |0and of sufficiently large internal diameter to enclose the locking nut 93. A larger diameter aligned bore I9 is provided in the tubular projection ||3, thus forming a shoulder |20 between the two diameter portions. A bearing seal |2| is provided within the larger diameter bore ||9 as best illustrated in Figure 5 of the drawings.

The seal |2| includes a resilient compressible l washer |22 of neoprene or similar material which is corrugated and is compressible longitudinally. A sea-ling ring |23 is supported on the end of the flexible washer |22. This sealing ring |23 is provided with a flange |24 of an external diameter to slide within the bore ||9 and is provided with a shoulder |25 which seals against the xed shoulder |20. The flexible washer |22 and the sealing ring |23 rotate in unison with the shaft I0 and with the impeller support 85 and hub 81 thereon.

The tubular projection I4 is likewise provided with a two diameter aperture |26 which accommodates a sea-ling element |21 similar to the sealing element |2| just described. The sealing elements V|2| and |21 serve to prevent ,the leakage ofliquid from the impeller chambers about-the yin communication with the inlet passage |32, best illustrated in Figure 4 of the drawings. As the impeller 83 continues to rotate a partial vacuum is formed behind the trailing edge |3| within the chamber 11 drawing liquid from the inlet |32. This operation continues until the leading edge |33 of the impeller 83 passes the inlet port |32. The leading edge |33 of theimpeller continues to force iiuid forwardly toward the outlet passage |34 until this leading edge passes the outlet port During the time of the intake stroke of the impeller 83, the impeller 34 is sealed so that there is no return passage from the outlet port |34 to the inlet port |32. As illustrated in Figure 4 of the drawings the impeller 84 is sealed with respect to both the boss and the boss 3| at the start of the intakestroke of the impeller 83 illustrated. .As .the impeller 84 rotates in a counterclockwise position from the position shown in Figure 4, the leading edge |35 thereof passes the in- .let port |32 and this leading edge forces fluid and are held from longitudinal movement by their bearing supports and a bearing support is provided on either side of Ithe pinions |3 and |4, thus firmly supporting these shafts for rotation. The gear housing isl entirely sealed from the Ypump housing and no grease or oil can leak from the gear housing into the pump housing. Similarly no fluid may leak from the impeller housing into the gear chamber.y

In addition to the spaced bearings within, the Igear casing I provide additional outboard bearings |5 and H6 which support the free ends of the impeller shafts and prevents any tendency for these shafts to flex or whip. The bearings ||5 and ||5 are sealed from the pumping charnber and the construction is such that the force against the shafts tending to move the same longitudinally is equalized. As a result the pump may Voperate with a minimum of friction.

Sanitary pumps must be designed so that the pumping chamber may be entirely disassembled and cleaned at the end of each pumping operation. In order to take the pump apart, it is only necessary to unscrew the wing nuts 15 from the studs 14, whereupon the cover plate ||0 may be removed. Once the cover plate l0 has been removed the nuts 93 and 96 holding the impellers in place are accessible. These nuts may be removed for cleaning purposes. Once the nuts 93 and 96 have been removed the seals |2| and |21 may be removed. The impellers 83 and 84 may be removed, the inner seals |33 and. |09 may be removed, and the entire impeller housing ported against said shoulder, a longitudinally compressible gasket interposed between said sealing ring and said impeller support, a cover plate carried by said impeller housing and together with said housing enclosing said impellers, and said impeller supports, a two diameter aperture through said cover plate axially aligned with, and encircling, each shaft, the two diameter portions forming a shoulder between the ends of the aperture, a sealing ring rotatably engageable against each said last named shoulder, and a longitudinally compressible gasket interposed between each said last named sealing ring and said impeller support.

6. A sanitary pump including a gear housing, a pair of substantially parallel shafts projecting therefrom, an impeller housing encricling said projecting shafts, tubular bosses on said impeller housing encircling each shaft, said impeller housing and said tubular bosses forming intersecting ring shaped impeller chambers, impeller supports encircling each shaft adjacent the end of said tubular bosses, impellers on said impeller supports rotatable in said ring shaped impeller chambers, a two diameter passage through said tubular bosses forming a shoulder between the ends thereof, a sealing ring rotatably supported against said shoulder, a longitudinally compressible gasket interposed between said sealing ring and said impeller support, a cover plate carried by said impeller housing and together with said housing enclosing said impeller supports, and said impellers, a pair of tubular projections on said cover plate concentric with said shafts, a two diameter passage through each of said projections forming shoulders intermediate the ends of the projections, a sealing ring engageable with each said last named shoulder, and a longitudinally compressible sealing gasket between each last named sealing ring and said impeller support.

7. A sanitary pump including a gear housing, a pair of substantially parallel shafts projecting therefrom, an impeller housing encircling said projecting shafts, tubular bosses on said impeller housing encircling each shaft, said impeller housing and said tubular bosses forming intersecting ring shaped impeller chambers, impeller supports encircling each shaft adjacent the end of said tubular bosses, impellers on said impeller supports rotatable in said ring shaped impeller chambers, a two diameter passage through said tubular bosses forming a shoulder between the ends thereof, a sealing ring rotatably supported against said shoulder, a longitudinally compressible gasket interposed between said sealing ring and said impeller support, a cover plate carried by said impeller housing and together with said housing enclosing said impeller supports, and said impellers, a pair of tubular projections on said cover plate concentric with said shafts, a two diameter passage through each of said projections forming shoulders intermediate the ends of the projections, a sealing ring engageable with each said last named shoulder, a longitudinally compressible sealing gasket between each last named sealing ring and said impeller support, and bearing means in each of said projections encircling the respective shafts for supporting the adjacent ends of said shafts.

8. A sanitary pump including a gear housing, a pair of substantially parallel shafts projecting therefrom, an impeller housing encircling said projecting shafts, tubular bosses on said impeller housing encircling each shaft, said impeller housing and said tubular bosses forming intersecting ring shaped impeller chambers, impeller supports encircling each shaft adjacent the end yof said tubular bosses, impellers on said impeller supports rotatable in said ring shaped impeller chambers, a two diameter passage through said tubular bosses forming a shoulder between the ends thereof, a sealing ring rotatably supported against said shoulder, a longitudinally compressible gasket interposed between said sealing ring and said impeller support, a cover plate carried by said impeller housing and together with said housing enclosing said impeller supports, and said impellers, a pair of tubular projections on said cover plate concentric with said shafts, Va two diameter passage through each of said projections forming shoulders intermediate the ends of the projections, a sealing ring engageable with each said last named shoulder, a longitudinally compressible sealing gasket between each last named sealing ring and said impeller support, bearing means in each of said projections encircling the respective shafts for supporting the adjacent ends of said shafts, and aperture means through said projections between said bearing means and said shoulders therein.

FRANCESCO COILURA.

REFERENCES CITED The following references are of record in the file of this patent:V

UNITED STATES PATENTS Number Name Date 1,642,454 Malmstrom Sept. 13, 1927 2,161,729 Thomson June 6, 1939 2,193,273 Dietzel Mar. 12, 1940 2,228,933 Thomson Jan. 14, 1941 2,279,136 Funk Apr. 7, 1942 2,407,753 Wallgren Sept. 17, 1946 FOREIGN PATENTS Number Country Date 16,098 Great Britain July 29, 1908 544,526 Great Britain Apr. 16, 1942 

